There are 2 main sources of guidance in Islam. First is The Quran – which is considered as The Word of God – which is an unchanged text since it was revealed 1,400 years ago. It has same number of verses (6,236) and same number of words (77,430) no matter which version of The Quran you pick.
The second source of guidance is Hadith – which is the word of The Prophet Muhammad (PBUH). There are many compilations of Hadith. There are 6 primary texts which are considered authentic, although according to their compilers, only some of the Hadith in those volumes are regarded 'authentic' while the others are 'weak'. Even the most authentic book of Hadith – known as Al-Bukhari – has only 2,600 (out of ~7,000) of its Hadith considered as 'authentic' by its compiler. The rest of them he considers as 'weak'; that means, these could be fabrications.
Then, there are more volumes of Hadith which are not considered authentic by a large number of Muslim scholars, but they somehow drag on.
While it was very difficult, almost impossible, to change the words of The Quran. Fabricating a new Hadith was a common thing during the early days of Islam. Those with vested interests started to fabricate Hadith right after the passing of Muhammad (PBUH). Throughout the courts in Islamic realm, people came with fabricated Hadiths to support their cases. This lead to an explosive growth of fabricated Hadiths to the extent that a Hadith could be presented to bolster any viewpoint so far-fetched that it could be outright rejected just upon listening it. “The practice had become so rampant that Ibn Abi al-Awja was executed in 722 CE in Kufa after confessing that he had fabricated four thousand Hadiths to serve his purposes.” Those in authority tried their best to stamp out these fakeries but to their dismay, fabricators were successfully able to play with the sensitivities of people and a huge body of Hadiths is still a part of Islamic tradition that is in complete opposition to the message of The Quran.
Word 'Houri/Hoor' has gained considerable negative connotations among the critics of Islam. They blame, based upon the interpretation of Quran by illiterate mullahs, that Hourie is a sexual partner/slave that will be given to Muslim men when they go to Heaven. This is an incorrect interpretation and needs immediate attention especially in the presence of such outlandish and vulgar fabricated hadiths: Sunan Ibn Majah, Volume 5, Book 37, Hadith 4337—“Abu Umama narrated: "The Messenger of God said, 'Everyone that God admits into Paradise will be married to 72 wives; two of them are houris and seventy of his inheritance of the female dwellers of hell. All of them will have libidinous sex organs and he will have an ever-erect penis.” Such are the hadith that will put any sensible (or not) Muslim to shame and this is something that he/she will never able to share with another person (and there is no need to, its fake). There is also another hadith which tells that every martyr will get 72 houris in Paradise as a reward. This Hadith has been attacked by the critics of Islam that it creates terrorists who, hoping to get many sexual partners/slaves, commit acts of terrorism against non-Muslims. Once, I came across a tweet (on Twitter), the author of which believed that English word 'whore' is derived from Arabic word 'Hoor' (houri). He might have thought that after learning that the Catholic Church is disparagingly called 'The Whore of The Babylon'. Obviously, there is no basis of word 'whore' deriving from 'houri'. The meaning of the latter will be discussed shortly while the former is derived variously from old Frisian 'hor' (meaning 'fornication'), old Norse 'hora' (meaning 'adulteress') or old English 'hore' (meaning 'prostitute'/'harlot'). Thus, there is an urgent need to clarify who or what a 'houri' is in the light of The Quran!
First of all, in all of 6236 verses of Quran, word 'Hoor' (houri) - that may means 'some sort of women' (although, the word itself is gender neutral, so it may mean a male or a female) is mentioned only 4 times.
In 56:22, those in the Paradise will have 'Hoor' with large eyes.
In 55:72, those in Paradise will have 'Hoor' (women) residing in pavilions.
In 52:20, those in Paradise will be married to 'Hoor' with large eyes.
Lastly, in 44:54, those in Paradise will be married to 'Hoor' with large eyes.
In none of the 4 places, Hoor are mentioned as a reward for martyrdom.
Nowhere in Quran, reward for martyrdom is carnal pleasures; in fact any kind of carnal acts or desires in paradise are not mentioned in Quran at all, though Quran gives a detailed description of Paradise, the rivers, garden, pavilions, thrones, clothes of silk, utensils of gold & silver, fruits & drinks, all of these and the pleasure of company of righteous family members, served by youth and lastly, the company of 'Hoors'. At no place Quran talks about 'Hoors' as objects of sexual affection. In the Paradise, there may not be any acts of sex at all, there may be neither any need nor a desire of that.
We can check what other words are derived from the same root as 'Hoor'. The words derived from triliteral root H-W-R appear a total of 13 times in Quran.
4 of them have been described above.
1 in 84:14 means 'return' to Allah (SWT), that means become His disciple again or be in contact with Him, socialise with Him.
2 in 18:34 & 18:37 mean 'talking' to each other, that means socialising.
5 in 3:52, 5:111, 5:112 & 61:14 (twice) mean 'disciples', that means socialising with some people who are your followers.
1 in 58:1 means 'dialogue', that also means socialising.
Based upon all the words in Quran that are derived from root H-W-R, we can be fairly certain that all these words mean some sort of 'socialising'. So, a 'Hoor', who can be a male or a female, will be a person who will be a social companion of the people of the Paradise.
Thus, according to Quran, a Hoor will be a male or a female social companion, not a sex slave. But, what about the Hadith? There are 2 criteria to judge a Hadith:
Quran is also known as 'Furqan', which means 'a criterion' to judge anything regarding laws of God. So, if there is a conflict between Quran & Hadith, Quran is supposed to be used as 'The Criterion' to judge the authenticity of the Hadith.
The second criteria to judge a Hadith is simple reasoning - described in Quran as 'Aqal'. Quran talks about using reason almost 50 times. (The above argument is an example of using reason).
Finally, for those who know Urdu language, like me, another word derived from trilateral root H-W-R (in Urdu) is 'Hawari' which means a 'supporter' or 'follower'. It is a commonly used word and it's never meant to be associated with any sexual intent or acts.